ASTM E2818-11(2019)
(Practice)Standard Practice for Determination of Quasistatic Fracture Toughness of Welds
Standard Practice for Determination of Quasistatic Fracture Toughness of Welds
SIGNIFICANCE AND USE
5.1 This test practice provides a recommended procedure for preparing fracture toughness specimens from welds to improve the likelihood of obtaining useful fracture toughness values.
5.1.1 The subsequent fracture toughness values, that have significance and use as stated in the applicable ASTM test method, may allow for flaw tolerance assessments of welded structures. Flaw tolerance assessments require an understanding and compensation for the differences that may exist between laboratory test results and field conditions.
5.1.2 The shallow-notched specimen testing procedures described in Annex E of ISO 15653 may be used by agreement between the parties involved as long as it is understood that Annex E is “Informative” and the result is a geometry dependent measurement of toughness that is not validated by the applicable test standard.
SCOPE
1.1 This practice provides methods for preparing specimens from welds in metallic materials and interpreting subsequent test results when used in conjunction with standards Test Methods E1290 and E1820 for the determination of fracture toughness. The fatigue pre-cracking procedures included in this practice may also be used to aid in preparing straight pre-cracks for weld specimens in accordance with Test Method E1681.
1.2 This practice draws heavily from ISO 15653: Metallic materials – Method of test for the determination of quasistatic fracture toughness of welds. All references to ISO 12135 in that test method should be replaced with the applicable ASTM Test Methods (E1820, E1290 or E1681).
1.3 The recommended specimen is a single-edge bend [SE(B)] with width, W, equal to twice the specimen thickness, B. An alternate SE(B) specimen with W/B equal to one and a span, S, to W ratio of 4 may be used but may produce different toughness values. A compact tension [C(T)] specimen may be used if it can be demonstrated that the analysis of results properly accounts for weld-to-base metal strength mismatch effects on fracture toughness.
1.4 The recommended limitation on weld-to-base metal yield strength ratio is
Undermatching within this limitation leads to conservative estimates of fracture toughness, while overmatching may lead to an overestimation of the fracture toughness by up to 10%.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E2818 − 11 (Reapproved 2019)
Standard Practice for
Determination of Quasistatic Fracture Toughness of Welds
This standard is issued under the fixed designation E2818; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This practice provides methods for preparing specimens
ization established in the Decision on Principles for the
from welds in metallic materials and interpreting subsequent
Development of International Standards, Guides and Recom-
test results when used in conjunction with standards Test
mendations issued by the World Trade Organization Technical
Methods E1290 and E1820 for the determination of fracture
Barriers to Trade (TBT) Committee.
toughness. The fatigue pre-cracking procedures included in
this practice may also be used to aid in preparing straight
2. Referenced Documents
pre-cracks for weld specimens in accordance withTest Method
2.1 ASTM Standards:
E1681.
E8/E8M Test Methods for Tension Testing of Metallic Ma-
1.2 This practice draws heavily from ISO 15653: Metallic
terials
materials – Method of test for the determination of quasistatic
E1290 Test Method for Crack-Tip Opening Displacement
fracture toughness of welds. All references to ISO 12135 in
(CTOD) Fracture Toughness Measurement (Withdrawn
that test method should be replaced with the applicableASTM 3
2013)
Test Methods (E1820, E1290 or E1681).
E1681 Test Method for Determining Threshold Stress Inten-
sityFactorforEnvironment-AssistedCrackingofMetallic
1.3 The recommended specimen is a single-edge bend
Materials
[SE(B)] with width, W, equal to twice the specimen thickness,
E1820 Test Method for Measurement of Fracture Toughness
B. An alternate SE(B) specimen with W/B equal to one and a
E1823 TerminologyRelatingtoFatigueandFractureTesting
span, S, to W ratio of 4 may be used but may produce different
2.2 ISO Standard:
toughness values. A compact tension [C(T)] specimen may be
used if it can be demonstrated that the analysis of results ISO 12135 Metallic materials – Unified method of test for
the determination of quasistatic fracture toughness
properly accounts for weld-to-base metal strength mismatch
effects on fracture toughness. ISO 15653 Metallic materials–Method of test for the deter-
mination of quasistatic fracture toughness of welds
1.4 The recommended limitation on weld-to-base metal
yield strength ratio is
3. Terminology
weld
σ
ys
3.1 Terminology of E1823 and ISO 15653 are applicable to
0.5, ,1.5 (1)
base
σ
ys
this test practice with the following additions.
Undermatching within this limitation leads to conservative
3.2 Definitions:
estimates of fracture toughness, while overmatching may
lead to an overestimation of the fracture toughness by up to 3.2.1 base metal yield strength—The base metal 0.2% offset
base
10%.
yield strength ~σ ! is defined by testing tensile specimens per
ys
Test Method E8/E8M.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.2.1.1 Discussion—ISO 15653 uses R to represent the
p0,2b
responsibility of the user of this standard to establish appro-
base metal yield strength.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
This practice is under the jurisdiction ofASTM Committee E08 on Fatigue and the ASTM website.
Fracture and is the direct responsibility of Subcommittee E08.07 on Fracture The last approved version of this historical standard is referenced on
Mechanics. www.astm.org.
Current edition approved Nov. 1, 2019. Published November 2019. Originally Available from International Organization for Standardization (ISO), 1, ch. de
approved in 2011. Last previous edition approved in 2011 as E2818–11. DOI: la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://
10.1520E2818-11R19. www.iso.ch.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2818 − 11 (2019)
weld
σ
6. Apparatus
ys
3.2.2 overmatched—Any weldment having .1
base
σ
ys
6.1 The apparatus for specimen preparation and testing is as
3.2.3 test temperature—The test temperature for tensile
described in ISO 15653 and the applicable ASTM fracture
specimens shall either be identical to the test temperature for
toughness test method.
the fracture toughness specimens, or evidence shall be pro-
vided to demonstrate that there is not an appreciable change in
7. Specimen Configuration, Dimensions, and Preparation
the yield strength between the test temperature used for the
7.1 The following sections override ISO 15653 where
tensile and fracture toughness tests.
applicable.
weld
σ
ys
7.1.1 Specimen:
3.2.4 undermatched—Any weldment having ,1
base
σ
ys
7.1.1.1 Standard Configuration—A single edge notch bend,
3.2.5 weldmetalyieldstrength—Theweldmetal0.2%offset
SE(B), specimen having a ratio of width W to thickness B
weld
yield strength σ is defined by testing tensile specimens per
~ !
ys
(W/B) of two and a span S to W ratio of four is the standard
Test Method E8/E8M.
configuration.
7.1.1.2 Alternative Configuration—A specimen having
3.2.5.1 Discussion—ISO 15653 uses R to represent the
p0,2w
W/B=1 may also be tested with a S/W=4. However, this
weld metal yield strength.
configuration may produce different toughness values than the
4. Summary of Practice standard configuration.
7.1.1.3 Shallow-crack SE(B) specimen testing—When the
4.1 This test practice complements ISO 15653 for the
microstructure of interest in a weld occurs only at a location
quasistatic fracture toughness testing of welds. When testing
where the precrack in a SE(B) specimen must be placed at a/W
welds, it is important that the crack tip sample the region and
< 0.45, conducting a fracture test will sample the toughness of
microstructure of interest. Procedures given in ISO 15653 for
that microstructure; however, it is subject to low constraint
selecting a specimen orientation, positioning of the fatigue
conditions that will elevate the measured toughness. If this
precrack relative to the weld or heat affected zone (HAZ), and
microstructure only occurs at this a/W, then the measured
verifying that the resulting measured fracture toughness is
fracture toughness is representative of the weld. On the other
representative of the target region or microstructure apply to
hand, if the microstructure could occur at deep crack locations
this practice.
in some applications, then the measured fracture toughness
4.2 This test practice references ISO 15653 for recommen-
could be non-conservative. Consequently, the shallow-notched
dations for relieving non-uniform residual stresses ahead of
specimen testing procedures described in Annex E of ISO
notch tips in weld fracture toughness specimens to allow for an
15653 may be used by agreement between the parties involved
improvement in the straightness of fatigue precracks. Where
as long as it is understood that Annex E is “Informative” and
thermal stress relief treatments are found inadequate, the local
the result is a geometry dependent measurement of toughness.
compression technique, which involves indenting the sides of
7.1.1.4 Alternative Specimen—The compact tension, C(T),
the specimens to encompass the notch tip, is the recommended
specimen, which is routinely used to measure fracture tough-
procedure.
ness for base materials, is not recommended for fracture
toughness testing of weldments due to a lack of experience
4.3 This practice follows the guidance provided in ISO
with both the testing and analysis of welded C(T) specimens.
15653 for relaxation in crack front straightness requirements
The C(T) specimen may be used if the user demonstrates that
provided in the applicable fracture toughness test method;
the equations for interpreting the results appropriately account
however, this relaxation is valid only for SE(B) specimens
for weld-to-base metal strength mismatch effects on fracture
evaluated in terms of J or CTOD (not for K evaluation).
Ic
toughness.
5. Significance and Use 7.1.1
...
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